Cyclic fasting bolsters cholesterol biosynthesis inhibitors' anticancer activity

Identifying oncological applications for drugs that are already approved for other medical indications is considered a possible solution for the increasing costs of cancer treatment. Under the hypothesis that nutritional stress through fasting might enhance the antitumour properties of at least some non-oncological agents, by screening drug libraries, we find that cholesterol biosynthesis inhibitors (CBIs), including simvastatin, have increased activity against cancers of different histology under fasting conditions. We show fasting's ability to increase CBIs' antitumour effects to depend on the reduction in circulating insulin, insulin-like growth factor-1 and leptin, which blunts the expression of enzymes from the cholesterol biosynthesis pathway and enhances cholesterol efflux from cancer cells. Ultimately, low cholesterol levels through combined fasting and CBIs reduce AKT and STAT3 activity, oxidative phosphorylation and energy stores in the tumour. Our results support further studies of CBIs in combination with fasting-based dietary regimens in cancer treatment and highlight the value of fasting for drug repurposing in oncology.

Survival Differences in High-Risk Prostate Cancer By Age

PURPOSE

Age is an established determining factor in survival in low-risk prostate cancer (PC), being this evidence weaker in high-risk tumors. Our aim is to evaluate the survival of patients with high-risk PC treated with curative intent and to identify differences across age at diagnosis.

METHODS

We did a retrospective analysis of patients with high-risk PC treated with surgery (RP) or radiotherapy (RDT) excluding N+ patients. We divided patients by age groups: <60, 60-70 and >70 years. We performed a comparative survival analysis.A multivariate analysis adjusted for clinically relevant variables and initial treatment received was performed.

RESULTS

Of a total of 2383 patients, 378 met the selection criteria with a median follow-up of 8.9 years: 38 (10.1%) <60 years, 175 (46.3%) between 60-70 years, and 165 (43.6%) >70 years. Initial treatment with surgery was predominant in the younger group (RP:63.2%, RDT:36.8%), and with radiotherapy in the older group (RP:17%, RDT:83%) (p=0.001). In the survival analysis, significant differences were observed in overall survival, with better results for the younger group. However, these results were reversed in biochemical recurrence-free survival, with patients <60 years presenting a higher rate of biochemical recurrence at 10 years. In the multivariate analysis, age behaved as an independent risk variable only for overall survival, with a HR of 2.8 in the group >70 years (95%CI: 1.22-6.5; p=0.015).

CONCLUSION

In our series, age appeared to be an independent prognostic factor for overall survival, with no differences in the rest of the survival rates.

Population based study of morbidity and mortality rates associated to radical prostatectomy cases in Spain

INTRODUCTION

There is no population-based study that accounts for the number of radical prostatectomies (RP) carried out in Spain, nor regarding the morbidity and mortality of this intervention. Our objective is to study the morbidity and mortality of RP in Spain from 2011 to 2015 and to evaluate the geographic variation.

MATERIAL AND METHODS

We designed a retrospective observational study of all patients submitted to RP in Spain during five consecutive years (2011-2015). The data was extracted from the «Conjunto Mínimo Básico de Datos» (CMBD). We have evaluated geographic variations in terms of morbidity and hospital stay, and the impact of the mean annual surgical volume for each center on these variables.

RESULTS

Between 2011-2015, a total of 37,725 RPs were performed in 221 Spanish public hospitals. The mean age of the series was 63.9±3.23 years. Of all RPs, 50% were performed through an open approach, and 43.4% have been operated on in hospitals with <500 beds. We observed an important variability in the distribution of the cases operated on in the different regions. The regions that perform more RPs are Andalusia, Catalonia, Galicia, and Madrid. Our study shows a complication rate of 8.6%, with hemorrhage and the need for transfusion being the most frequent (5.3 and 4%, respectively). There are significant differences in bleeding rates and hospital stay among regions, which are maintained after adjusting for patient characteristics and type of hospital. When studying the annual surgical volume of each hospital, we find that the impact on the rate of hemorrhage or transfusion is linear; however, hospital stay remains stable at around 5 days from 60 RPs/year.

CONCLUSIONS

In national terms, morbidity and mortality rates after RP are comparable to those described in the literature. This study reveals a clear dispersion in the hospitals that carry out this intervention, showing clear differences in terms of morbidity and hospital stay between the different regions.

Abstract 3020: Periodic fasting and cholesterol biosynthesis inhibitors achieve a synergistic antitumor activity in gastrointestinal cancers

Periodic fasting enhances the activity of several chemotherapeutics, molecularly-targeted drugs, endocrine agents and immune checkpoint inhibitors. Identifying drugs that are approved for non-oncological conditions, but acquire antitumor properties through fasting could pinpoint new cancer cell liabilities and define new treatment options. By screening over 800 approved drugs in PK9 pancreatic ductal adenocarcinoma (PDAC) cells, we identified several azoles (antifungal agents), including clotrimazole (CTZ), as agents whose cytotoxic activity against cancer cells is synergistically enhanced by starvation conditions. Since azoles inhibit 14alpha-demethylase, which is a key enzyme for cholesterol (CE) biosynthesis, we hypothesized that starvation and azoles would cooperate by blunting CE production in PDAC cells. Consistent with this notion, we found that simvastatin (an HMG-CoA reductase inhibitor) and terbinafine (TRB), which obstruct squalene epoxidase (SQLE), another key enzyme from the CE biosynthetic pathway, also had their antitumor effects strongly enhanced by starvation. Combined starvation and CTZ or starvation and TRB reduced intracellular CE in Capan-1 cells both in vitro and in vivo. Methyl-beta-cyclodextrin, which depletes intracellular CE, and starvation also showed a synergistic interaction in Capan-1 and in MiaPaCa2 cells (another PDAC cell line). Finally, culture media supplementation with a water-soluble CE formulation prevented the synergistic interaction between starvation and CE biosynthesis inhibitors. TRB potentiation through starvation was countered through supplementation with insulin, IGF1 and leptin, which are downregulated during fasting. Consistent with CE being an essential constituent of membrane lipid rafts, that harbor the growth- and survival-promoting PI3K/AKT signaling cascade, we found combined CTZ or TRB and starvation to markedly downregulate phosphorylated AKT in Capan-1 xenografts. Similar results were obtained in MiaPaCa2 cells. Capan-1 cell transduction with constitutively active, myristoylated AKT protected them from combined CTZ or TRB and starvation, indicating that AKT inhibition mediates the synergistic interaction between CE production inhibitors and fasting. Weekly 48h fasting enhanced CTZ and TRB antitumor effects in vivo in Capan-1 xenograft-bearing mice and, when combined with TRB, lowered circulating LDL (while increasing HDL) cholesterol as compared to TRB alone. Overall, these findings support the potential of fasting-based diets in combination with CE biosynthesis inhibitors against PDAC.

Citation Format: Amr Khalifa, Ana Guijarro, Asmaa Namatalla, Moustafa Ghanem, Matteo Lambertini, Alessio Nencioni, Irene Caffa. Periodic fasting and cholesterol biosynthesis inhibitors achieve a synergistic antitumor activity in gastrointestinal cancers [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 3020.

Influence of androgen deprivation therapy on the severity of COVID-19 in prostate cancer patients

BACKGROUND

The TMPRSS2 protein has been involved in severe acute respiratory syndrome caused by coronavirus 2 (SARS-CoV-2). The production is regulated by the androgen receptor (AR). It is speculated that androgen deprivation therapy (ADT) may protect patients affected by prostate cancer (PC) from SARS-CoV-2 infection.

METHODS

This is a retrospective study of patients treated for COVID-19 in our institution who had a previous diagnosis of PC. We analyzed the influence of exposure of ADT on the presence of severe course of COVID-19.

RESULTS

A total of 2280 patients were treated in our center for COVID-19 with a worse course of disease in males (higher rates of hospitalization, intense care unit [ICU] admission, and death). Out of 1349 subjects registered in our PC database, 156 were on ADT and 1193 were not. Out of those, 61 (4.52%) PC patients suffered from COVID-19, 11 (18.0%) belonged to the ADT group, and 50 (82.0%) to the non-ADT group. Regarding the influence of ADT on the course of the disease, statistically significant differences were found neither in the death rate (27.3% vs. 34%; p = 0.481), nor in the presence of severe COVID-19: need for intubation or ICU admission (0% vs. 6.3%; p = 0.561) and need for corticoid treatment, interferon beta, or tocilizumab (60% vs. 34.7%; p = 0.128). Multivariate analysis adjusted for clinically relevant comorbidities did not find that ADT was a protective factor for worse clinical evolution (risk ratio [RR] 1.08; 95% confidence interval [CI], 0.64-1.83; p = 0.77) or death (RR, 0.67; 95% CI, 0.26-1.74; p = 0.41).

CONCLUSIONS

Our study confirms that COVID-19 is more severe in men. However, the use of ADT in patients with PC was not shown to prevent the risk of severe COVID-19.

P–488 Patients’ attitudes towards the anonymity of gamete donation in Spain

Study question

To what extent do infertility patients in Spain support different forms of anonymity for oocyte and sperm donation?

Summary answer

Most patients who undergo treatment with donated gametes in Spain consider that their children should not know the identity of the donors.

What is known already

Spain has a large tradition of gamete donation, probably influenced by its law that requires gamete donation to be anonymous for the donor and the recipient. Although there is a growing support for openness and identity-release in gamete donation, Spanish Society of Fertility has generated an Anonymity in Donations Framework Document which recommends revelation to the donor-conceived children their biological origin preserving the identity. However, there is no information on what the preferences of the patients are regarding the disclosure of the origins to their children.

Study design, size, duration

A prospective, cross-sectional multicenter study that includes all eleven clinics in Spain and involves women who had used donated gametes. From September to October 2020, a self-administered questionnaire was sent out to a total of 57 women which were asked to indicate their responses on a 7-point Likert. 57 (100%) women anonymously completed the questionnaire.

Participants/materials, setting, methods

The participants were asking for their socio-demographic characteristics, their opinions concerning secrecy or disclosure of the method of conception towards the child, what type of information should the child have access to – identifying or non-identifying – and whether they intend to inform their child and relatives about his/her origin. Statistical analysis was performed with Chi square test for dichotomous variables and one-sample T-Student for Likert items. p &lt; 0.05 was considered significant.

Main results and the role of chance

Unlike homosexual or single women, 60% of heterosexual couples refuse to inform their offspring about the origin of their gametes and 47,5% would not tell anyone.

Patients do not want to know the identity of donors (0,276 p˂0,001) and they consider that knowledge about the origin of the gametes (0,278 p˂0,001) or the identity of the donor (0,178 p˂0,001) is not important to a child.

Patients do not believe that the donor has the right to know the identity of the offspring (0.098 p &lt; 0.001) but they agree with his/her right to anonymity (0.679).

Limitations, reasons for caution

While the multicenter study design and the extraction of a complete time series from the population under study strengthens validity, the study is limited to women, without being able to extrapolate the results to men or children born by gamete donation, which constitutes a limitation.

Wider implications of the findings: The findings of this study can be used as a basis for further discussion between regulators and professionals with respect to anonymity related to donor conception. These opinions should be considered carefully in legal and ethical discussions on gamete donation.

Trial registration number

Not applicable

SIRT6 enhances oxidative phosphorylation in breast cancer and promotes mammary tumorigenesis in mice

BACKGROUND

Sirtuin 6 (SIRT6) is a NAD⁺-dependent deacetylase with key roles in cell metabolism. High SIRT6 expression is associated with adverse prognosis in breast cancer (BC) patients. However, the mechanisms through which SIRT6 exerts its pro-oncogenic effects in BC remain unclear. Here, we sought to define the role of SIRT6 in BC cell metabolism and in mouse polyoma middle T antigen (PyMT)-driven mammary tumors.

METHODS

We evaluated the effect of a heterozygous deletion of Sirt6 on tumor latency and survival of mouse mammary tumor virus (MMTV)-PyMT mice. The effect of SIRT6 silencing on human BC cell growth was assessed in MDA-MB-231 xenografts. We also analyzed the effect of Sirt6 heterozygous deletion, of SIRT6 silencing, and of the overexpression of either wild-type (WT) or catalytically inactive (H133Y) SIRT6 on BC cell pyruvate dehydrogenase (PDH) expression and activity and oxidative phosphorylation (OXPHOS), including respiratory complex activity, ATP/AMP ratio, AMPK activation, and intracellular calcium concentration.

RESULTS

The heterozygous Sirt6 deletion extended tumor latency and mouse survival in the MMTV-PyMT mouse BC model, while SIRT6 silencing slowed the growth of MDA-MB-231 BC cell xenografts. WT, but not catalytically inactive, SIRT6 enhanced PDH expression and activity, OXPHOS, and ATP/AMP ratio in MDA-MB-231 and MCF7 BC cells. Opposite effects were obtained by SIRT6 silencing, which also blunted the expression of genes encoding for respiratory chain proteins, such as UQCRFS1, COX5B, NDUFB8, and UQCRC2, and increased AMPK activation in BC cells. In addition, SIRT6 overexpression increased, while SIRT6 silencing reduced, intracellular calcium concentration in MDA-MB-231 cells. Consistent with these findings, the heterozygous Sirt6 deletion reduced the expression of OXPHOS-related genes, the activity of respiratory complexes, and the ATP/AMP ratio in tumors isolated from MMTV-PyMT mice.

CONCLUSIONS

Via its enzymatic activity, SIRT6 enhances PDH expression and activity, OXPHOS, ATP/AMP ratio, and intracellular calcium concentration, while reducing AMPK activation, in BC cells. Thus, overall, SIRT6 inhibition appears as a viable strategy for preventing or treating BC.

[Recommendations on bladder cancer Management during COVID-19 pandemia: lessons learned and future plans.]

The guidelines and recommendation sof good clinical practice have been disrupted by new and urgent policies, marked by the COVID-19 pandemic. Urothelial carcinoma has a significant prevalence in Spain, whose population has been greatly affected by COVID-19, directly by the disease and indirectly by the confinement. The objective of this work is to offer recommendations on protocols and guidelines adjusted to different phases of the pandemic. MATERIAL AND METHODS: This document on the management of bladder carcinoma is based on few evidence on urological oncological practice during the first months of the pandemic and on the authors' experience in this pathology during the crisis of COVID-19. Hospital experts in infectious disseases and radiology have participated to design a common strategy to reorganize the activity. RESULTS: Different proposals for treatment and follow-up of patients diagnosed with bladder cancer adjusted for oncological risk and the different phases of the pandemic are presented. CONCLUSIONS: The pandemic's spread was unimaginable just a few months ago. Health systems have been shaken by the disease in the most critical phases. It is necessary, at this time, to make an additional effort to develop tools that can facilitate the care of bladder carcinoma and minimize the impact and risks for patients and health professionals in the future.

Progenitor Cells Activated by Platelet Lysate in Human Articular Cartilage as a Tool for Future Cartilage Engineering and Reparative Strategies

Regenerative strategies for human articular cartilage are still challenging despite the presence of resident progenitor cell population. Today, many efforts in the field of regenerative medicine focus on the use of platelet derivatives due to their ability to reactivate endogenous mechanisms supporting tissue repair. While their use in orthopedics continues, mechanisms of action and efficacy need further characterization. We describe that the platelet lysate (PL) is able to activate chondro-progenitor cells in a terminally differentiated cartilage tissue. Primary cultures of human articular chondrocytes (ACs) and cartilage explants were set up from donor hip joint biopsies and were treated in vitro with PL. PL recruited a chondro-progenitors (CPCs)-enriched population from ex vivo cartilage culture, that showed high proliferation rate, clonogenicity and nestin expression. CPCs were positive for in vitro tri-lineage differentiation and formed hyaline cartilage-like tissue in vivo without hypertrophic fate. Moreover, the secretory profile of CPCs was analyzed, together with their migratory capabilities. Some CPC-features were also induced in PL-treated ACs compared to fetal bovine serum (FBS)-control ACs. PL treatment of human articular cartilage activates a stem cell niche responsive to injury. These facts can improve the PL therapeutic efficacy in cartilage applications.

MYC-Associated Factor MAX is a Regulator of the Circadian Clock

The circadian transcriptional network is based on a competition between transcriptional activator and repressor complexes regulating the rhythmic expression of clock-controlled genes. We show here that the MYC-associated factor X, MAX, plays a repressive role in this network and operates through a MYC-independent binding to E-box-containing regulatory regions within the promoters of circadian BMAL1 targets. We further show that this "clock" function of MAX is required for maintaining a proper circadian rhythm and that MAX and BMAL1 contribute to two temporally alternating transcriptional complexes on clock-regulated promoters. We also identified MAX network transcriptional repressor, MNT, as a fundamental partner of MAX-mediated circadian regulation. Collectively, our data indicate that MAX regulates clock gene expression and contributes to keeping the balance between positive and negative elements of the molecular clock machinery.

Prostate cancer adverse pathology reclassification in patients undergoing active surveillance in a long-term follow-up series

BACKGROUND

Active surveillance (AS) has become a valid option for patients with a very low risk of prostate cancer (PC) with a widespread application. There are still a few series, with a medium follow-up longer than 5 years, reporting data on pathological upgrading. The objective is to evaluate the changes in surveillance biopsies of patients with low-risk PC in a long-term follow-up and determine if a longer stay in AS could involve worse pathological findings.

MATERIALS AND METHODS

A retrospective analysis of our institutional database of patients with PC undergoing AS during 2004 to 2018 was performed. The inclusion criteria were prostate-specific antigen (PSA) ≤ 10 ng/mL, Gleason grade 1 and T1c/T2a. Patients were assessed by serum PSA level and digital rectal examination at 6-month intervals. Transrectal ultrasound-guided prostate biopsies were performed during the first year of follow-up, and every 2 or 3 years thereafter. The pathology details of biopsies were analyzed and compared with the current series on AS.

RESULTS

Three-hundred nineteen patients undergoing AS were evaluated with a median follow-up of 5.3 years and a mean age of 67.4 years. Sixty-three patients did not meet all the criteria to be considered low-risk PC but were included in the analysis. Overall, 128 patients (40.1%) underwent active treatment (84.7% of them due to pathological progression in surveillance biopsies). The proportion of patients with a reported upgrading ranged between 19.4% and 35.3%, although only the fourth biopsy showed an upgrading proportion of over 30%. Limitations include the retrospective design of the study and the existence of different protocols between other cohorts that make it difficult to compare their results.

CONCLUSIONS

For patients who remained in surveillance the percentage of upgrading increased slightly with the time, being more frequent after the third-surveillance biopsy. These findings support the importance of extending surveillance biopsies for patients who remain candidates for curative treatment.

The value of tumour weight as a predictive factor for recurrence and progression in non-muscle invasive bladder cancer

Objective: To further assess the influence of the weight after TURBT as a predictive factor for recurrence and progression in NMIBC.Materials and methods: A cohort of patients with a first episode of NMIBC between 1999 and 2016 was analysed retrospectively. We studied the correlation between the tumour's size and weight, the time-dependent ROC curves for the optimal weight value for the prediction of recurrence and progression and their association with the risk of recurrence and progression at one and five years.Results: We analysed 470 patients who met inclusion criteria. Median (IQR) follow-up time was four years (2.2-6.7), 227 (48.3%) patients had a recurrence and 46 (9.8%) progressed. Median (IQR) weight after resection was 2 g (0.8-6) and its correlation with size was 0.56. The optimal value for the prediction of recurrence was 4 g. The RFS at one and five years with a weight <4 g was 77.7% and 53.5%, respectively, compared to 57.8% and 34.7% with higher weight (p < .001). PFS at one and five years was 98% and 92.7% for a weight <4 g compared to 91.4% and 83.1% for tumours >4 g, respectively (p = .02). On multivariate analysis, a higher weight was associated with an increased risk of recurrence: HR [95%:CI] = 1.52[1.05-1.86], and progression: HR[95%:CI] = 1.87[1.01-3.47] (p < .05).Conclusion: The weight of the specimen obtained after TURBT is a predictive factor of both recurrence and progression in NMIBC that may be more accurate than tumour size and easily and objectively measured. An increase of 52% and 87% in the risk of recurrence and progression, respectively, was found in tumours weighing more than 4 g.

A giant exoplanet orbiting a very-low-mass star challenges planet formation models

Surveys have shown that super-Earth and Neptune-mass exoplanets are more frequent than gas giants around low-mass stars, as predicted by the core accretion theory of planet formation. We report the discovery of a giant planet around the very-low-mass star GJ 3512, as determined by optical and near-infrared radial-velocity observations. The planet has a minimum mass of 0.46 Jupiter masses, very high for such a small host star, and an eccentric 204-day orbit. Dynamical models show that the high eccentricity is most likely due to planet-planet interactions. We use simulations to demonstrate that the GJ 3512 planetary system challenges generally accepted formation theories, and that it puts constraints on the planet accretion and migration rates. Disk instabilities may be more efficient in forming planets than previously thought.

Usefulness of Genetic Study by Next-generation Sequencing in High-risk Arrhythmogenic Cardiomyopathy

INTRODUCTION AND OBJECTIVES

Arrhythmogenic right ventricular cardiomyopathy (ARVC) is an inherited cardiomyopathy characterized by progressive fibrofatty replacement of predominantly right ventricular myocardium. This cardiomyopathy is a frequent cause of sudden cardiac death in young people and athletes. The aim of our study was to determine the incidence of pathological or likely pathological desmosomal mutations in patients with high-risk definite ARVC.

METHODS

This was an observational, retrospective cohort study, which included 36 patients diagnosed with high-risk ARVC in our hospital between January 1998 and January 2015. Genetic analysis was performed using next-generation sequencing.

RESULTS

Most patients were male (28 patients, 78%) with a mean age at diagnosis of 45 ± 18 years. A pathogenic or probably pathogenic desmosomal mutation was detected in 26 of the 35 index cases (74%): 5 nonsense, 14 frameshift, 1 splice, and 6 missense. Novel mutations were found in 15 patients (71%). The presence or absence of desmosomal mutations causing the disease and the type of mutation were not associated with specific electrocardiographic, clinical, arrhythmic, anatomic, or prognostic characteristics.

CONCLUSIONS

The incidence of pathological or likely pathological desmosomal mutations in ARVC is very high, with most mutations causing truncation. The presence of desmosomal mutations was not associated with prognosis.

Influence of carbon dioxide stunning procedure on quality of turkey meat

1. The objective of this study was to evaluate the effect of sex and gas stunning on quality attributes of turkey breast meat. 2. One hundred B.U.T. Premium turkeys (50 males and 50 females) were divided into four groups of 25 animals and subjected to one of two CO₂ stunning procedures: G1 stepwise (step 1: 30% CO₂, 15 s; step 2: 55% CO₂, 40 s; step 3: 70% CO₂, 45 s) or G2 fixed concentration (80% CO₂, 100 s). The pH and meat colour at 20 min post-mortem, and pH, colour (L*, a*, b*), water holding capacity (WHC), drip loss (DL), cooking loss (CL) and Warner-Bratzler shear force (WBSF) in breast samples at 24 h and 7 d post-mortem were assessed. 3. There were significant differences between stunning groups for pH, meat colour and CL, whereas no significant differences were found for DL and WBSF. Sex had a significant effect on pH and b* and ageing of meat affected pH, colour coordinates, DL and WBSF. 4. It was concluded that the G2 treatment affected negatively the pH value and colour coordinates. However, G2 stunning affected positively the WHC parameters. Female turkeys had better results than males for pH, and the colour of female turkey breast meat was less yellow than male breast meat.

The 67P/Churyumov-Gerasimenko observation campaign in support of the Rosetta mission

We present a summary of the campaign of remote observations that supported the European Space Agency's Rosetta mission. Telescopes across the globe (and in space) followed comet 67P/Churyumov-Gerasimenko from before Rosetta's arrival until nearly the end of the mission in September 2016. These provided essential data for mission planning, large-scale context information for the coma and tails beyond the spacecraft and a way to directly compare 67P with other comets. The observations revealed 67P to be a relatively 'well-behaved' comet, typical of Jupiter family comets and with activity patterns that repeat from orbit to orbit. Comparison between this large collection of telescopic observations and the in situ results from Rosetta will allow us to better understand comet coma chemistry and structure. This work is just beginning as the mission ends-in this paper, we present a summary of the ground-based observations and early results, and point to many questions that will be addressed in future studies.This article is part of the themed issue 'Cometary science after Rosetta'.

Influence of the location and number of metastases in the survival of metastatic prostatic cancer patients

INTRODUCTION

The prognosis of patients diagnosed with metastatic prostate cancer seems to be modulated by factors such as the number and site of metastases. Our objective is to evaluate survival outcomes according to the number and site of metastases in our series of metastatic patients over the last 15 years.

MATERIALS AND METHODS

A retrospective analysis was performed on patients diagnosed between 1998 and 2014. We analyzed overall survival and progression-free survival, depending on the number and location of metastases on patients with newly diagnosed metastatic prostate cancer. Other potential prognostic factors were also evaluated: age, clinical stage, PSA at diagnosis, Gleason, PSA nadir, time till PSA nadir and first-line or second-line treatment after progression.

RESULTS

We analyzed a series of 162 patients. The mean age was 72.7yr (SD: 8.5). The estimated median overall survival was 3.9 yr (95% CI 2.6-5.2). The overall survival in patients with only lymph node metastases was 7 yr (95% CI 4.1-9.7), 3.9 (95%CI 2.3-5.5) in patients with only bone metastases, 2.5 yr (95% CI 2-2.3) in lymph nodes and bone metastases, and 2.2 yr (95% CI 1.4-3) in patients with visceral metastases (P<.001). In multivariate analysis, the location of metastasesis significantly associated with overall survival and progression-free survival. The number of metastases showed no association with survival.

CONCLUSIONS

The site of metastases has a clear impact on both overall survival and progression-free survival. Patients with only lymph node involvement had a better prognosis. The number of metastases showed no significant impact on survival in our series.

Variability in complications and operative mortality after radical cystectomy in Spain

BACKGROUND

In the literature, mortality for radical cystectomy (RC) varies between 2.3% and 7.5%. In Spain, there are no published general data on morbidity and mortality.

OBJECTIVE

To identify the complications and mortality of RC in Spain through an analysis of all procedures performed over a 3-year period and to study the geographic variability of these results.

MATERIAL AND METHODS

We identified patients who underwent RC in the Spanish National Health System between 2011 and 2013 based on the minimum basic data set. We analysed the complications and mortality during hospitalisation and at 30, 60 and 90 days. We compared these results in the various autonomous communities, adjusted them by age, Charlson score and sex and subsequently added the hospital size.

RESULTS

We studied 7999 patients who underwent RC in 197 hospitals of the Spanish National Health System. The mean age of the series was 67.2±9.8 years. The median stay was 15 days (IQR, 11-24). Some 47.2% of the patients had complications. The mean mortality in-hospital and at 30, 60 and 90 days was 4.7, 2.9, 5 and 6.2%, respectively. There was considerable variability in the mortality at 90 days among the communities (3.8-9.1%). When adjusting by the patient and hospital characteristics, there were still significant geographic variations (3.8-11.5%).

CONCLUSIONS

RC mortality in Spain at 90 days is similar to the rate in the literature. There are significant geographic variations unexplained by the characteristics of the patients or by those of the hospitals in which these operations were performed.

Diagnostic yield and complications of extended lymphadenectomy versus limited lymphadenectomy combined with radical prostatectomy

BACKGROUND

Lymphadenectomy for prostate cancer (PC) is the most reliable procedure for detecting lymphatic metastases. The optimal extension of this procedure is still a topic of debate.

OBJECTIVE

To analyse the diagnostic performance and complications of extended lymphadenectomy (ELD) and limited lymphadenectomy (LLD) in a series of patients with high-risk PC who underwent radical prostatectomy (RP).

MATERIAL AND METHODS

A retrospective study was conducted on patients with high d'Amico risk who underwent RP with lymphadenectomy between 1999 and 2014. A comparative analysis was performed of the diagnostic capacity of lymphatic metastases of ELD and LLD and of postoperative complications at 90 days.

RESULTS

Ninety-three patients were analysed, 20 (21.5%) and 73 (78.5%) of whom underwent ELD and LLD, respectively. The mean age of the series was 65.26 years (SD, 5.51). The median follow-up was 1.51 (0.61-2.29) years in the ELD group and 5.94 (3.61-9.10) in the LLD group. The median number of nodes obtained was 13 (9-23) in the ELD group compared with 5 (2-8) in the LLD group (p <.001). The percentages of patients with positive nodes in the ELD and LLD groups were 35% and 5.47%, respectively (p <.001). The overall complication rate at 90 days was 35.5% (33 patients). In the ELD group, 12 patients (60%) had complications, compared with 21 patients (28.8%) in the LLD group (p=.016), with no significant differences in severity according to the Clavien scale (p=.73).

CONCLUSIONS

In our series, the detection of metastatic nodes was significantly greater with ELD. ELD increases the number of complications, with no differences compared with LLD in severity according to the modified Clavien scale.

Long-term oncological outcomes of an active surveillance program in recurrent low grade Ta bladder cancer

INTRODUCTION

Over the last 2 decades, there has been a major increase in active surveillance (AS) as a therapeutic alternative in urological tumors regarded to be of low risk. Owing to the findings of significant clinical outcomes in our series, this report presents an update of our AS program in patients with recurrent non-muscle-invasive bladder tumor. The objective was to confirm the oncological long-term safety of this protocol and to determine possible variables associated with progression.

MATERIALS AND METHODS

Cohort of patients included in AS between 1999 and 2014.

INCLUSION CRITERIA

recurrent papillary tumors, previous pTa-pT1, G1-G2, shorter than 1cm, and fewer than 5 tumour sites.

EXCLUSION CRITERIA

prior G3, CIS (carcinoma in situ), or positive-result cytology. All patients underwent close monitoring with flexible cystoscopy every 3 to 4 months for the first 2 years. After this time, follow-ups were conducted every 6 months, alternating between cystoscopy and ultrasound. Urinary cytology test was performed at all visits.

RESULTS

In all, 252 AS periods in 186 patients were studied, with a median follow-up of 6 years. Out of all periods, 203 (80.6%) underwent active treatment. After remaining under observation, 86.4% had not progressed in stage, and 79.3% in grade. Of these patients, 4 experienced progression to T2; all of them were previously T1G2.

CONCLUSIONS

AS in a high-selectivity group of patients with recurrent non-muscle-invasive bladder tumor is feasible and oncologically safe in the long term. Patients with previous history of T1 should not be included in AS protocols even when very small recurrences are diagnosed.

Effects of peripheral FAAH blockade on NTG-induced hyperalgesia--evaluation of URB937 in an animal model of migraine

BACKGROUND

Systemic nitroglycerin (NTG) activates brain nuclei involved in nociceptive transmission as well as in neuroendocrine and autonomic functions in rats. These changes are considered relevant for migraine because NTG consistently provokes spontaneous-like migraine attacks in migraineurs. Several studies have suggested a relationship between the endocannabinoid levels and pain mediation in migraine. URB937, a peripheral inhibitor of fatty acid amide hydrolase (FAAH)-the enzyme that degrades anandamide, produces analgesia in animal models of pain, but there is no information on its effects in migraine.

AIM

We evaluated whether URB937 alters nociceptive responses in the animal model of migraine based on NTG administration in male rats, using the tail flick test and the plantar and orofacial formalin tests, under baseline conditions and after NTG administration. Furthermore, we investigated whether URB937 affects NTG-induced c-Fos expression in the brain.

RESULTS

During the tail flick test, URB937 showed an antinociceptive effect in baseline conditions and it blocked NTG-induced hyperalgesia. URB937 also proved effective in counteracting NTG-induced hyperalgesia during both the plantar and orofacial formalin tests. Mapping of brain nuclei activated by NTG indicates that URB937 significantly reduces c-Fos expression in the nucleus trigeminalis caudalis and the locus coeruleus.

CONCLUSIONS

The data suggest that URB937 is capable of changing, probably via indirect mechanisms, the functional status of central structures that are important for pain transmission in an animal model of migraine.

Effects of acute stress on cardiac endocannabinoids, lipogenesis, and inflammation in rats

OBJECTIVE

Trauma exposure can precipitate acute stress (AS) and cardiovascular disorders (CVD). Identifying AS-related physiologic changes that affect CVD risk could inform development of early CVD prevention strategies. The endocannabinoid system (ECS) regulates hypothalamic-pituitary-adrenal axis and stress-related cardiovascular function. We examine stress-related ECS activity and its association with cardiovascular biochemistry/function after AS.

METHODS

Rodents (n = 8-16/group) were exposed to predator odor or saline; elevated plus maze, blood pressure, serum and cardiac ECS markers, and lipid metabolism were assessed 24 hours and 2 weeks postexposure.

RESULTS

At 24 hours, the predator odor group demonstrated anxiety-like behavior and had a) elevated serum markers of cardiac failure/damage (brain natriuretic peptide: 275.1 versus 234.6, p = .007; troponin I: 1.50 versus 0.78, p = .076), lipogenesis (triacylglycerols: 123.5 versus 85.93, p = .018), and inflammation (stearoyl delta-9 desaturase activity: 0.21 versus 0.07, p < .001); b) decreased cardiac 2-arachidonoyl-sn-glycerol (29.90 versus 65.95, p < .001), oleoylethanolamide (114.3 versus 125.4, p = .047), and palmitoylethanolamide (72.96 versus 82.87, p = .008); and c) increased cardiac inflammation (interleukin [IL]-1β/IL-6 ratio: 19.79 versus 13.57, p = .038; tumor necrosis factor α/IL-6 ratio: 1.73 versus 1.03, p = .019) and oxidative stress (thiobarbituric acid reactive substances: 7.81 versus 7.05, p = .022), which were associated with cardiac steatosis (higher triacylglycerol: 1.09 versus 0.72, p < .001). Cardiac lipogenesis persisted, and elevated blood pressure emerged 2 weeks postexposure.

CONCLUSIONS

Acute psychological stress elicits ECS-related cardiac responses associated with persistent, potentially pathological changes in rat cardiovascular biochemistry/function.

Brown adipose tissue quantification in human neonates using water-fat separated MRI

There is a major resurgence of interest in brown adipose tissue (BAT) biology, particularly regarding its determinants and consequences in newborns and infants. Reliable methods for non-invasive BAT measurement in human infants have yet to be demonstrated. The current study first validates methods for quantitative BAT imaging of rodents post mortem followed by BAT excision and re-imaging of excised tissues. Identical methods are then employed in a cohort of in vivo infants to establish the reliability of these measures and provide normative statistics for BAT depot volume and fat fraction. Using multi-echo water-fat MRI, fat- and water-based images of rodents and neonates were acquired and ratios of fat to the combined signal from fat and water (fat signal fraction) were calculated. Neonatal scans (n = 22) were acquired during natural sleep to quantify BAT and WAT deposits for depot volume and fat fraction. Acquisition repeatability was assessed based on multiple scans from the same neonate. Intra- and inter-rater measures of reliability in regional BAT depot volume and fat fraction quantification were determined based on multiple segmentations by two raters. Rodent BAT was characterized as having significantly higher water content than WAT in both in situ as well as ex vivo imaging assessments. Human neonate deposits indicative of bilateral BAT in spinal, supraclavicular and axillary regions were observed. Pairwise, WAT fat fraction was significantly greater than BAT fat fraction throughout the sample (ΔWAT-BAT = 38 %, p<10(-4)). Repeated scans demonstrated a high voxelwise correlation for fat fraction (Rall = 0.99). BAT depot volume and fat fraction measurements showed high intra-rater (ICCBAT,VOL = 0.93, ICCBAT,FF = 0.93) and inter-rater reliability (ICCBAT,VOL = 0.86, ICCBAT,FF = 0.93). This study demonstrates the reliability of using multi-echo water-fat MRI in human neonates for quantification throughout the torso of BAT depot volume and fat fraction measurements.

Pharmacological characterization of the peripheral FAAH inhibitor URB937 in female rodents: interaction with the Abcg2 transporter in the blood-placenta barrier

BACKGROUND AND PURPOSE

URB937 is a peripherally restricted inhibitor of the anandamide-deactivating enzyme fatty-acid amide hydrolase (FAAH). Despite its limited access to the CNS, URB937 produces marked antinociceptive effects in rodents. URB937 is actively extruded from the CNS by the ATP-binding cassette (ABC) membrane transporter, Abcg2. Tissue Abcg2 levels are markedly different between males and females, and this transporter is known to limit the access of xenobiotics to the fetoplacental unit in gestating female rodents. In the present study, we investigated the tissue distribution and antinociceptive properties of URB937 in female mice and rats.

EXPERIMENTAL APPROACH

We studied the systemic disposition of URB937 in female mice and the antinociceptive effects of this compound in models of visceral (acetic acid-induced writhing) and inflammatory nociception (carrageenan-induced hyperalgesia) in female mice and rats. Furthermore, we evaluated the interaction of URB937 with the blood-placenta barrier in gestating mice and rats.

KEY RESULTS

Abcg2 restricted the access of URB937 to the CNS of female mice and rats. Nevertheless, URB937 produced a high degree of antinociception in female mice and rats in models of visceral and inflammatory pain. Moreover, the compound displayed a restricted access to placental and fetal tissues in pregnant mice and rats.

CONCLUSIONS AND IMPLICATIONS

Peripheral FAAH blockade with URB937 reduces nociception in female mice and rats, as previously shown for males of the same species. In female mice and rats, Abcg2 limits the access of URB937, not only to the CNS, but also to the fetoplacental unit. LINKED ARTICLES This article is part of a themed section on Cannabinoids. To view the other articles in this section visit http://dx.doi.org/10.1111/bph.2012.167.issue-8.

2-arachidonoylglycerol signaling in forebrain regulates systemic energy metabolism

The endocannabinoid system plays a critical role in the control of energy homeostasis, but the identity and localization of the endocannabinoid signal involved remain unknown. In the present study, we developed transgenic mice that overexpress in forebrain neurons the presynaptic hydrolase, monoacylglycerol lipase (MGL), which deactivates the endocannabinoid 2-arachidonoyl-sn-glycerol (2-AG). MGL-overexpressing mice show a 50% decrease in forebrain 2-AG levels but no overt compensation in other endocannabinoid components. This biochemical abnormality is accompanied by a series of metabolic changes that include leanness, elevated energy cost of activity, and hypersensitivity to β(3)-adrenergic-stimulated thermogenesis, which is corrected by reinstating 2-AG activity at CB(1)-cannabinoid receptors. Additionally, the mutant mice are resistant to diet-induced obesity and express high levels of thermogenic proteins, such as uncoupling protein 1, in their brown adipose tissue. The results suggest that 2-AG signaling through CB(1) regulates the activity of forebrain neural circuits involved in the control of energy dissipation.

Peripheral antinociceptive effects of inhibitors of monoacylglycerol lipase in a rat model of inflammatory pain

BACKGROUND AND PURPOSE The endocannabinoid 2-arachidonoylglycerol (2-AG) is degraded primarily by monoacylglycerol lipase (MGL). We compared peripheral antinociceptive effects of JZL184, a novel irreversible MGL inhibitor, with the reversible MGL-preferring inhibitor URB602 and exogenous 2-AG in rats. EXPERIMENTAL APPROACH Nociception in the formalin test was assessed in groups receiving dorsal paw injections of vehicle, JZL184 (0.001-300 µg), URB602 (0.001-600 µg), 2-AG (ED(50)), 2-AG + JZL184 (at their ED(50)), 2-AG + URB602 (at their ED(50)), AM251 (80 µg), AM251 + JZL184 (10 µg), AM630 (25 µg) or AM630 + JZL184 (10 µg). Effects of MGL inhibitors on endocannabinoid accumulation and on activities of endocannabinoid-metabolizing enzymes were assessed. KEY RESULTS Intra-paw administration of JZL184, URB602 and 2-AG suppressed early and late phases of formalin pain. JZL184 and URB602 acted through a common mechanism. JZL184 (ED(50) Phase 1: 0.06 ± 0.028; Phase 2: 0.03 ± 0.011 µg) produced greater antinociception than URB602 (ED(50) Phase 1: 120 ± 51.3; Phase 2: 66 ± 23.9 µg) or 2-AG. Both MGL inhibitors produced additive antinociceptive effects when combined with 2-AG. Antinociceptive effects of JZL184, like those of URB602, were blocked by cannabinoid receptor 1 (CB(1)) and cannabinoid receptor 2 (CB(2)) antagonists. JZL184 suppressed MGL but not fatty-acid amide hydrolase or N-arachidonoyl-phosphatidylethanolamine phospholipase D activities ex vivo. URB602 increased hind paw 2-AG without altering anandamide levels. CONCLUSIONS AND IMPLICATIONS MGL inhibitors suppressed formalin-induced pain through peripheral CB(1) and CB(2) receptor mechanisms. MGL inhibition increased paw skin 2-AG accumulation to mediate these effects. MGL represents a target for the treatment of inflammatory pain.

Central and peripheral endocannabinoids and cognate acylethanolamides in humans: association with race, adiposity, and energy expenditure

CONTEXT

Peripheral and central endocannabinoids and cognate acylethanolamides (AEs) may play important but distinct roles in regulating energy balance.

OBJECTIVE

We hypothesized that in humans central/peripheral endocannabinoids are differently associated with adiposity and energy expenditure and differ by race.

DESIGN

We examined associations of arachindonoylethanolamide, 2-arachidonoylglycerol, palmitoylethanolamide, and oleoylethanolamide (OEA) assayed in plasma and cerebrospinal fluid (CSF) with race, adiposity, and energy expenditure.

SETTING/PARTICIPANTS

In this monitored clinical inpatient study, CSF was obtained by lumbar puncture in 27 individuals (12 Caucasian, 11 American Indian, and four African-American). Twenty-four hour and sleep energy expenditure were measured by indirect calorimetry in a respiratory chamber.

MAIN OUTCOME MEASURE

Samples were analyzed from a previous study originally designed to test a blood-brain barrier leptin transport deficit in human obesity.

RESULTS

CSF (but not peripheral) 2-arachidonoylglycerol was significantly increased in American Indians compared with Caucasians (18.48 ± 6.17 vs. 10.62 ± 4.58 pmol/ml, P < 0.01). In the whole group, peripheral AEs were positively but in CSF negatively associated with adiposity. However, in multivariate models adjusted for the other peripheral and CSF AEs, peripheral arachindonoylethanolamide was the only AE significantly associated with adiposity. Interestingly, CSF OEA concentrations were positively associated with adjusted 24 hour and sleep energy expenditure (r = 0.47, P < 0.05; r = 0.42, P < 0.05), but peripheral OEA was not.

CONCLUSIONS

These data indicate a central alteration of the endocannabinoid system in American Indians and furthermore show that AEs in both compartments play an important but distinct role in human energy balance regulation.

CD36 gene deletion decreases oleoylethanolamide levels in small intestine of free-feeding mice

Oleoylethanolamide (OEA) is an endogenous lipid mediator that decreases food intake and enhances lipid catabolism. Dietary fat stimulates OEA mobilization in the proximal small intestine, through a mechanism that requires the participation of the membrane glycoprotein CD36 (fatty acid translocase, FAT). CD36 is highly expressed in small-intestinal enterocytes and is involved in fatty acid uptake and intracellular signaling. Here, we analyze the impact of genetic CD36 deletion on OEA production in various mouse tissues under free-feeding conditions and at different times of the light/dark cycle. CD36 ablation decreases OEA levels in jejunum and plasma during the dark phase, when mice consume most of their daily food. CD36 deletion is also associated with reduced OEA levels in kidney, but not in other tissues including duodenum, stomach, adrenals, white and brown fat, heart, liver, pancreas, skeletal muscle and brain. The results underscore the important role of CD36 in jejunal OEA production linked to feeding.

Melatonin receptors in brain areas and ocular tissues of the teleost Tinca tinca: characterization and effect of temperature

The aim of the present study was to characterize the central melatonin receptors in brain areas and ocular tissues of the teleost Tinca tinca. We investigated the temperature-dependence of 2-iodo-melatonin ([(125)I]Mel) binding in the optic tectum-tegmentum area and the neural retina. The binding of [(125)I]Mel showed a widespread distribution in brain and ocular tissues, with the highest density in the optic tectum-thalamus and the lowest in hindbrain. The [(125)I]Mel affinity was similar in all the studied tissues, and it was on the order of the low pM range. Saturation, kinetic and pharmacological studies showed the presence of a unique MT(1)-like melatonin binding site. In addition, the non-hydrolysable GTP analog, the GTPgammaS, and sodium cations induced a specific binding decrease in the optic tectum and neural retina, suggesting that such melatonin binding sites in the tench are coupled to G protein. Thus, these melatonin binding sites in optic tectum and neural retina fulfil the requirements of a real hormone receptor, the specific binding is rapid, saturable, and reversible, and is inhibited by GTP analogs. Additionally, a clear effect of temperature on such central melatonin receptors was found. Temperature did not modify the B(max) and K(d), but the kinetics of [(125)I]Mel binding resulted in a highly thermosensitive process in both tissues. Both association and dissociation rates (K(+1) and K(-1)) significantly increased with assay temperature (15-30 degrees C), but the K(d) constant (estimated as K(-1)/K(+1)) remained unaltered. In conclusion, this high thermal dependence of the melatonin binding to its receptors in the tench central nervous system supports the conclusion that temperature plays a key role in melatonin signal transduction in fish.

Characterization of weight loss and weight regain mechanisms after Roux-en-Y gastric bypass in rats

Roux-en-Y gastric bypass (RYGB) is the most effective therapy for morbid obesity, but it has a ∼20% failure rate. To test our hypothesis that outcome depends on differential modifications of several energy-related systems, we used our established RYGB model in Sprague-Dawley diet-induced obese (DIO) rats to determine mechanisms contributing to successful (RGYB-S) or failed (RYGB-F) RYGB. DIO rats were randomized to RYGB, sham-operated Obese, and sham-operated obese pair-fed linked to RYGB (PF) groups. Body weight (BW), caloric intake (CI), and fecal output (FO) were recorded daily for 90 days, food efficiency (FE) was calculated, and morphological changes were determined. d-Xylose and fat absorption were studied. Glucose-stimulated vagal efferent nerve firing rates of stomach were recorded. Gut, adipose, and thyroid hormones were measured in plasma. Mitochondrial respiratory complexes in skeletal muscle and expression of energy-related hypothalamic and fat peptides, receptors, and enzymes were quantified. A 25% failure rate occurred. RYGB-S, RYGB-F, and PF rats showed rapid BW decrease vs. Obese rats, followed by sustained BW loss in RYGB-S rats. RYGB-F and PF rats gradually increased BW. BW loss in RYGB-S rats is achieved not only by RYGB-induced decreased CI and increased FO, but also via sympathetic nervous system activation, driven by increased peptide YY, CRF, and orexin signaling, decreasing FE and energy storage, demonstrated by reduced fat mass associated with the upregulation of mitochondrial uncoupling protein-2 in fat. These events override the compensatory response to the drop in leptin levels aimed at conserving energy.

Is a model useful in exploring the catabolic mechanisms of weight loss after gastric bypass in humans?

PURPOSE OF REVIEW

In the USA, approximately 3% of adults are morbidly obese, in whom behavior modification and drug therapy is ineffective in inducing major weight loss. Surgery is their only reliable option. The Roux-en-Y gastric bypass accounts for 90% of all bariatric surgeries because it achieves the best weight loss results. Many studies describe weight loss and changes in metabolic blood parameters after Roux-en-Y gastric bypass. We compare recent human data with the findings in our rats to validate the versatility of using a Roux-en-Y gastric bypass rat model to explore the multifactorial molecular and physiological dimensions of weight loss and weight regain.

RECENT FINDINGS

Not only mechanical factors but also changes in gastrointestinal and adipose hormones and hypothalamic neuropeptides contribute to Roux-en-Y gastric bypass induced weight loss by promoting catabolic processes. Nevertheless, the exact mechanisms of weight loss remain unknown.

SUMMARY

To investigate these catabolic mechanisms we used our Roux-en-Y gastric bypass rat model in diet induced obese rats. We found clear morphometric, physiological and biochemical parallelisms between humans and our rats. It is likely that Roux-en-Y gastric bypass induces similar changes in hypothalamic neuropeptides which can only be studied using the rat model. It therefore provides a useful research tool for exploring and studying the development of adjuvant antiobesity therapies.

Antimyopathic effects of carnitine and nicotine

PURPOSE OF REVIEW

The clinical course of most chronic diseases is associated with declined energy intake and nutrient-resistant progressive myopathy, characterized by accelerated proteolysis and impaired function. This anorexia/cachexia syndrome leads to deterioration of quality of life, and increased morbidity and mortality. The clinical efficacy of currently available therapeutic strategies is limited and more effective treatments are needed.

RECENT FINDINGS

Chronic systemic inflammation, triggered and sustained by cytokines, and increased oxidative stress contribute to the pathogenesis of the anorexia/cachexia syndrome. Carnitine and nicotine have recently been tested as immunomodulating and antioxidant agents. In particular, carnitine supplementation has been shown to reduce chronic inflammation and oxidative stress in hemodialysis patients and, in cancer patients, yielding to reduced fatigue and improved outcome. Nicotine is able to induce the anti-inflammatory activity of the vagus nerve. In animal models of sepsis and cancer, the nicotine-induced supplementation resulted in better protection of nutritional status and improved survival.

SUMMARY

In the continuous effort to develop more efficacious strategies against the anorexia/cachexia syndrome, carnitine and nicotine may represent a further therapeutic tool. More clinical studies are needed, however, before their use can be routinely suggested.

Catabolic effects of gastric bypass in a diet-induced obese rat model

PURPOSE OF REVIEW

In the USA, 8-10 million people are morbidly obese, which is associated with a high frequency of comorbidities. The most effective treatment is surgery. Of around 180,000 bariatric operations performed in 2005, 80% were Roux-en-Y gastric bypass, consisting of a small gastric pouch to minimize food intake and a Roux-en-Y of distal small bowel bypassing the upper gastrointestinal tract. The precise mechanisms whereby Roux-en-Y gastric bypass achieves sustained weight loss remain unknown. To gain insight into the catabolic events of sustained weight loss we developed a diet-induced obese Roux-en-Y gastric bypass rat model. We review our rat model data from the novel viewpoint of the catabolic state, comparing it with the limited human data available and the catabolic events occurring in cancer anorexia/cachexia syndrome.

RECENT FINDINGS

Current data suggest the involvement of mechanisms other than restrictive and malabsorptive factors of the Roux-en-Y gastric bypass, classically thought of as the mechanisms responsible for weight loss. Based on available data, gastrointestinal hormones and cytokines play a key role in reducing food intake and regulating energy homeostasis. Because of the cross talk between peripheral modulators and the hypothalamus, a critical role for their interaction in the outcome of Roux-en-Y gastric bypass is emerging.

SUMMARY

In our Roux-en-Y gastric bypass rat model many of the changes in gastrointestinal hormones, adipokines and cytokines as well as in hypothalamic neuropeptides and neurotransmitters resemble the changes observed in the anorexia/cachexia rat model, suggesting that Roux-en-Y gastric bypass triggers a catabolic state responsible for loss of appetite and prolonged body weight reduction.

Hypothalamic integration of immune function and metabolism

The immune and neuroendocrine systems are closely involved in the regulation of metabolism at peripheral and central hypothalamic levels. In both physiological (meals) and pathological (infections, traumas and tumors) conditions immune cells are activated responding with the release of cytokines and other immune mediators (afferent signals). In the hypothalamus (central integration), cytokines influence metabolism by acting on nucleus involved in feeding and homeostasis regulation leading to the acute phase response (efferent signals) aimed to maintain the body integrity. Peripheral administration of cytokines, inoculation of tumor and induction of infection alter, by means of cytokine action, the normal pattern of food intake affecting meal size and meal number suggesting that cytokines acted differentially on specific hypothalamic neurons. The effect of cytokines-related cancer anorexia is also exerted peripherally. Increase plasma concentrations of insulin and free tryptophan and decrease gastric emptying and d-xylose absorption. In addition, in obesity an increase in interleukin (IL)-1 and IL-6 occurs in mesenteric fat tissue, which together with an increase in corticosterone, is associated with hyperglycemia, dyslipidemias and insulin resistance of obesity-related metabolic syndrome. These changes in circulating nutrients and hormones are sensed by hypothalamic neurons that influence food intake and metabolism. In anorectic tumor-bearing rats, we detected upregulation of IL-1beta and IL-1 receptor mRNA levels in the hypothalamus, a negative correlation between IL-1 concentration in cerebro-spinal fluid and food intake and high levels of hypothalamic serotonin, and these differences disappeared after tumor removal. Moreover, there is an interaction between serotonin and IL-1 in the development of cancer anorexia as well as an increase in hypothalamic dopamine and serotonin production. Immunohistochemical studies have shown a decrease in neuropeptide Y (NPY) and dopamine (DA) and an increase in serotonin concentration in tumor-bearing rats, in first- and second-order hypothalamic nuclei, while tumor resection reverted these changes and normalized food intake, suggesting negative regulation of NPY and DA systems by cytokines during anorexia, probably mediated by serotonin that appears to play a pivotal role in the regulation of food intake in cancer. Among the different forms of therapy, nutritional manipulation of diet in tumor-bearing state has been investigated. Supplementation of tumor bearing rats with omega-3 fatty acid vs. control diet delayed the appearance of tumor, reduced tumor-growth rate and volume, negated onset of anorexia, increased body weight, decreased cytokines production and increased expression of NPY and decreased alpha-melanocyte-stimulating hormone (alpha-MSH) in hypothalamic nuclei. These data suggest that omega-3 fatty acid suppressed pro-inflammatory cytokines production and improved food intake by normalizing hypothalamic food intake-related peptides and point to the possibility of a therapeutic use of these fatty acids. The sum of these data support the concept that immune cell-derived cytokines are closely related with the regulation of metabolism and have both central and peripheral actions, inducing anorexia via hypothalamic anorectic factors, including serotonin and dopamine, and inhibiting NPY leading to a reduction in food intake and body weight, emphasizing the interconnection of the immune and neuroendocrine systems in regulating metabolism during infectious process, cachexia and obesity.

Effects of temperature on 2-[125I]-iodomelatonin binding to melatonin receptors in the neural retina of the frog Rana perezi

The present study analyzes the effect of temperature-dependent modifications on the binding of the analog 2-[125I]-melatonin to melatonin receptors in isolated neural retina membranes from the greenfrog Rana perezi. Association and dissociation rate constants (K+1, K-1) were exponentially increased by the assay temperature. At 15 degrees C, association and dissociation required several hours; meanwhile, at 35 degrees C, rate constants were 100- and 34-fold faster, respectively. However, the Kd constant calculated as K-1/K+1 was unmodified by the assay temperature. When frogs were acclimated at either 5 or 22 degrees C for 1 month, K+1, and K-1 constants determined at 15 and 25 degrees C were identical in both cold- and warm-acclimated groups. Thus, the binding kinetics of melatonin receptors in frog retinas did not shown any thermal compensation. Results from saturation curves and pharmacological profiles of melatonin binding sites support a lack of effect of assay temperature on the affinity of melatonin receptors in the frog retina. The inhibition of [125I]Mel binding by GTPgammaS showed clearly that the coupling of melatonin receptors to G proteins is temperature-dependent. Higher concentrations of the GTP analog were needed to inhibit specific binding when temperature decreased. The temperature effect on binding kinetics and on the G protein coupling to melatonin receptors suggests that the melatonin signal could be transduced distinctly depending on the temperature. Thus, temperature plays a major role, not only on melatonin synthesis, but also in the transduction of melatonin signal in ectotherms.

Characterization of melatonin binding sites in the brain and retina of the frog Rana perezi

The aim of this study was to characterize 2-[125I]iodomelatonin binding sites in the neural retina and central nervous system (telencephalon, diencephalon, and optic tectum) of the anuran amphibian Rana perezi. Saturation and kinetic studies and pharmacological characterization revealed the existence of a unique melatonin-binding site that belongs to the Mel 1 receptor subtype. The affinity of this site is similar in all tissues studied (Kd, 10.5-12.8 pM), but the density varied from diencephalon and optic tectum, which exhibit the highest density, to telencephalon with the lowest. Neural retina showed an intermediate receptor density. This melatonin-binding site fulfills the requirements of a real hormone receptor; the binding is saturable, reversible, and inhibited by different melatonin agonists and antagonists. The affinity order of ligands is: 2-phenyl-melatonin = 2-I-melatonin > 6-Cl-melatonin = melatoninz >> luzindole. Additionally, specific binding is decreased by non-hydrolysable GTP analogue, sodium, and by pretreatment of membranes with pertussis toxin. All these results suggest the existence of a widely distributed and pharmacologically homogeneous melatonin receptor of the subfamily Mel 1 in the nervous system of Rana perezi coupled to a Gi/o protein.